In the paper, the existence of positive solutions is studied for the second-order delay differential equation with a damping term ẍ(t) + a(t)ẋ(t) + b(t)x(h(t)) = 0 using a comparison with the integro-differential equation ẏ(t) + ∫t0t e -∫ts a(ξ)dξ b(s)y(h(s))ds = 0. Explicit non-oscillation criteria and comparison type results are derived.
- Integro-differential equation
- Positive solution
- Second order delay differential equation